The present invention relates to starter control circuits, and more particularly to starter control circuits for internal combustion engines.
A potential hazard of explosion exists whenever an engine is started in the presence of a combustible atmosphere such as gasoline or diesel oil. This problem particularly exists in boats having inboard or inboard/outboard engines wherein fuel fumes can accumulate in the engine compartment and create an explosive environment which can be ignited by the actuation of the boat's electric starting circuit. Accordingly, recommended procedures for starting this type of boat include first inspecting the engine compartment to determine if any such fumes may be present, or alternatively, completely ventilating the engine compartment prior to ignition. In some of the larger boats, forced draft ventilation systems have been provided in their engine compartments and the recommended procedure is to actuate this ventilation system prior to starting the engine. The U.S. Coast Guard has developed recommended ventilation operating times for the ventilation systems of specific boats which takes into consideration the size of the engine compartment and the operating characteristics of the ventilation system. These recommended ventilation times can range anywhere from under a minute to two minutes or more. These ventilation procedures and times are typically detailed in the instruction manuals for the boat and are presented on a reminder tag which is mounted by the control console of the boat.
While the above procedures will tend to provide for the proper ventilation of an engine compartment prior to starting, there is still the opportunity for error. There are numerous situations where the operator will forget to follow the standard starting procedures or will consciously decide to dispense with the ventilating step. Likewise, the situation will frequently occur that the ventilation system is not operated for sufficient time to properly purge the engine compartment of combustible fumes. In each of these situations the potential for an accidental explosion exists even though the boat is equipped with a forced draft ventilation system and procedures exist which are designed to obviate this hazard. Accordingly, there is a definite need for control system which insures proper ventilation of an engine compartment prior to starting the engine. Likewise, there is a need for a control system for a ventilation system which is automatically actuated when the operator starts the engine.